Mold Prep Day with Our Volunteers

On Sunday, April 23rd the Cast & Place team delivered a big day of work in preparation for our first full panel castings. It couldn’t have happened without Sergio, Josette and Julia, our great volunteers. They came down to meet us at Grounds for Sculpture to assemble the clay molds, cut sheetrock and get plenty dirty.

The day began with a big reveal - the first full panel cracked clay molds! We were thrilled to see the beautiful crack patterns and feel how strong the clay felt. We need robust clay to minimize breakage within the mold during the pour.

Scot looks happy as he inspects the molds

Ted set up a camera to make a time lapse of the clay drying and cracking. The action really starts around 1:00. Notice how the clay without a fan on it cracks more slowly. We also tried salt on the far right panel to increase the cracking but it didn’t have much effect.

What does seem to have an effect is inconsistencies in the clay mix. Here’s a close up shot of a chunk of clay that didn’t get broken down in the slurry. Cracks like to form around flaws and inconsistencies and this chunk did the trick.

The crack-making clay chunk

By the way, here’s the clay itself. It came in chunks of many sizes. We are turning it into slurry in a cement mixer.

Our clay in the morning light

The next step is to carefully transfer the clay fragments into the molds one fragment at a time. It’s a bit like an archaeological dig as we move fragments from the drying trays to the molds and adhere them to a piece of sheetrock. We need to lock them down so that they don’t move in the flow of the molten aluminum. There are two methods we are testing: 1) Two screws per piece of clay fragment so they don’t move or rotate 2) Fireproof adhesive. The adhesive has advantages. Smaller pieces can be locked down and there’s less risk of breaking the piece than with screws. We shall see.

Lisa carefully arranges the clay fragments

The color differences are due to the amount of moisture in each fragment

Later in the day, Josette and Lisa worked together on gluing pieces down. A slathering of fireproof adhesive on the bottom and careful placement keeps the crack pattern looking great.

Slather & Place

Josh, Sergio, Josette and Julia (Josette was everywhere) turned a big stack of sheetrock into mold parts, cutting each one by hand with the help of an enormous steel angle from one of the molds. Sergio (pulling a blade against the steel angle) was a cutting machine!

Cut, cut and cut

We ended up cutting the full stack of pieces. This effort will really help us get ahead of the game as the pour day approaches

Big sheetrock stack ready for mold assembly

Julia helped mark a 1” border around each “cap” piece of the mold so we knew where to lay out the clay.

Julia using Scot’s great trick to mark a line by pulling the square along the sheetrock edge

Scot and Bruce spent a good part of the day fabricating a new furnace just for the project. I think we all agreed that the furnace is a rather handsome piece of metal work.

Scot putting in the finishing touches on the furnace

Ted was busy assembling molds all day. When we were close to finishing up, he was cleaning out the clay trays in preparation for the next batch of slurry to be laid out for cracking.

Ted vacuums the empty clay trays in preparation for the next batch

Here’s the full team (except Bruce) as we left for the day! Thank you so much to Sergio, Josette and Julla, our “Cast & Place” volunteers! We couldn’t do it without you! We’re looking forward to many more volunteers being part of the process in the coming weeks as we pull the project together.